Papers by Keyword: Control Strategy

Abstract: Mixing and displacement air distribution are the main ventilation principles applied in both residential and non-residential buildings. Recently, personalized ventilation when the fresh air is delivered directly to the occupants at a high ventilation effectiveness has become an alternative. Despite of this fact, little research has been carried out to quantify the energy saving potential of personalized ventilation. This study aimed to quantify the effect of ventilation effectiveness and control strategy on the energy performance and thermal comfort for an open plan office equipped by different types of ventilation systems, including mixing ventilation with constant air volume, demand control ventilation and personalized ventilation. A model was created in a program for dynamic energy simulations TRNSYS, representing one floor of a typical office building divided into four zones with different orientations and a core. Space heating and cooling were provided by ceiling fancoil units recirculating the room air, thus the tasks of ventilation and air conditioning were provided by two separate systems. The potential of personalized ventilation to save energy for fans and for the heating coil of the ventilation system presented about 70% compared to constant air volume mixing ventilation, however, the overall saving was only 20% when also the energy demand for space heating was considered. The energy benefit of demand control ventilation and personalized ventilation depends on the energy need for space heating and cooling, system configuration and operation, and occupancy.

Abstract: Shift process of automatic transmission is divided into torque phases and inertia phase, and the control principle of clutch to clutch shift is studied with the lever method. Then, inertia phase engine and transmission integrated control principle and entire shift process engine and transmission integrated control principle are respectively studied with taking power on up shift as study example and taking the transmission output torque fluctuations during shifting minimum as control target. Simulation results are compared to the results of power on up shift without engine and transmission integrated control, and it is proved that the transmission output torque overshoot peak with inertia phase engine and transmission integrated control strategy is decreased significantly and shifting jerks are reduced. Shift quality is improved significantly.

Abstract: The disadvantage of Beijing-Tianjin-Tangshan power grid operation control mode is that the control effect is poorer and the spare capacity demand is big, this paper puts forward a new coordinated control strategy. First of all, this paper describes the relationship between the load, frequency, the output of generating unit, the tie line power and the area control error relationship of the whole power grid, according to the regional automatic generation control performance assessment criteria, concludes the characteristics of regional unit adjustment. This paper analyzes the contradiction between them, and then proposes a coordinated control strategy between the Beijing-Tangshan power grid and Tianjin power grid. The case simulation results prove the superiority and feasibility of the new coordinated control strategy. Compared with the original, the new strategy reduces the volatility of the unit, shortens the recovery time of frequency, and has a certain practical significance.

Abstract: To assemble easily damaged micro-parts safely in interference fit way, the assembly process is designed and the interaction force in assembly process is analyzed. The pose of micro-parts is aligned based on calibration of three microscopic vision systems from different directions. In addition, a control strategy based on feedback of vision and force is proposed to assemble safely. In the case of two micro-parts just contact, position of micro-part is adjusted based on force information to compensate pose alignment error and keep force in safe range. When micro-part is deformed as increased contact force, position of micro-part is adjusted based on force in the interference fit process and deformation of micro-part. Experimental results demonstrate the effectiveness of proposed methods.

Abstract: This paper is a survey on research status of the force-feedback master manipulator for teleoperation at home and abroad. The conclusion includes three aspects: mechanism configuration, control strategy and the model of people’s arms. The authors compared different theories already developed. Then they present the strengths and weaknesses of each theory. The conclusion is significant in pointing the direction for future study.

Abstract: A reasonable and effective control strategy for HEV (Hybrid Electric Vehicle) with HESS (Hybrid Energy Storage System) can improve the system efficiency and battery service life. A dynamic programming-based global optimal control strategy which fully considered the efficiency of each component in HEV is presented. To compare with the nonlinear proportion factor dynamic coordination strategy, the fuel consumption is not increased. The cycle numbers of battery are further decreased which benefits its cycle life improvement. The regenerative energy callback ratio improves 3% under the shanghai drive cycle as an example. Since this optimization algorithm considers efficiency of each subsystem, the efficiency optimum under the selected driving cycle was realized. It can also provide a reference for the non-linear scaling factor allocation strategies to determine the scale factors.

Abstract: Food waste management has become an important issue from the environmental, economic, and social points of view due to the fast increase of food waste production and serious environmental pollution. Food waste is considered to be an attractive feedstock of anaerobic digestion and has attracted worldwide attention because of its good biodegradability and high methane production potential. However, in practice, anaerobic digestion system of food waste often shows poor performance and stability, which greatly limited the development of anaerobic digestion process of food waste. In order to obtain high treatment efficiency and satisfactory methane yield, many researchers employed various control strategies for anaerobic digestion of food waste including pretreatment, additive agent addition, two-phase anaerobic digestion, and anaerobic co-digestion. Therefore, this article is intended to review the control strategies for anaerobic digestion process that have been developed for methane production from food waste.

Abstract: Resources of wind power due to its presence greater volatility, increasing the difficulty of regulating for the power grid. In the supply side, by installing thermal storage device to the cogeneration units so as to increase the adjusting capacity in the supply side of the power system, in the load side, the wind power heating system added heat storage device, increasing the load that can be adjusted. These two measures could be better to solve the problem that part of the abandoned wind. In this paper, analyzed the theoretical basis of each system briefly, added thermal storage device in electric –thermal combine system, and the thermal storage device installation position has been described too. Due mostly theoretical on thermal storage device is about the thermodynamic aspects, it is rather strange for electricity workers, so in this electrical-thermal combined system, its thermal storage devices and electric boiler thermal model have been made a simple analysis and described its control strategy. The control strategy was a comprehensive coordination to the power grid, meanwhile, taking into account the hysteresis characteristics, delay effects and daily regulation plan features of the thermodynamic parameters of thermal storage system make a reasonable start-stop control strategy finally.

Abstract: This paper introduces the work process and mechanism of the head-box, from the experimental point of view, analyzed the relationship between the head-box control parameters. The relationship between the level and the total pressure and the relationship between the fan pressure and total pressure is give. Through various experimental results, the control algorithm and strategy of the head-box is proposed. The practice shows that the total pressure control precision is about 3%.

Abstract: Micro-grid is to integrate a variety of distributed energy resources to weaken the adverse effects of decentralized distributed generation on a large grid, effective way to fully exploit the economic benefits of distributed generation.When large grid power quality appear, failure, power outages and other problems, micro-grid based on local information can be quickly switched to the state from the network, and under the jurisdiction of the load especially important to provide power to support the load, to avoid accidents.Therefore, micro-grid has become an important research focus and direction of development of distributed power generation field.The main thesis of the existing micro-grid operation control strategies to summarize, summarize, and control the operation of the micro-grid reference when choosing strategies.